Retroreflective marking system

ABSTRACT

Embodiments relate to a retroreflective marking system. A retroreflective marking system comprises a colorless binder, colored glass elements, and colored retroreflective elements, wherein the colored glass elements and colored retroreflective elements are positioned on top of the colorless binder such that color and retroreflectivity comes from the top of the system. This system also leads to improved skid resistance.

FIELD OF THE INVENTION

Embodiments relate to a marking system, particularly to a retroreflective marking system.

BACKGROUND OF THE INVENTION

Roadway markers are used on roadways to provide guidance and information to motorists and pedestrians. Current roadway marking systems first apply a colored binder and then drop glass beads on top of the colored binder. The colored binder generally includes expensive titanium oxide particles and other filler materials to provide white color and to reflect light back to a motorist. However, only the titanium oxide in the upper part of the coating is fully utilized in providing color and retroreflectivity. At the bottom part of the binder layer, the titanium oxide is practically useless. The colored binder may also include colored pigments if a color other than white is desired. However, if multiple colors are desired, paint lines must first be flushed of a first colored binder before a second colored binder is used, leading to a slow, inefficient, and wasteful process.

Further, current roadway marking systems using a binder and glass beads show no evidence of skid resistant properties.

Accordingly, there is a need for a simple, cost-effective marking system (e.g., roadway marking system) that provides adequate color, retroreflectivity, and skid resistance while eliminating the use of expensive titanium oxide.

SUMMARY OF THE INVENTION

Embodiments relate to a retroreflective marking system. A retroreflective marking system comprises a colorless binder, colored glass elements, and colored retroreflective elements, wherein the colored glass elements and colored retroreflective elements are positioned on top of the colorless binder such that color and retroreflectivity comes from the top of the system. This system also leads to improved skid resistance and allows for change between various colors without flushing lines.

In exemplary embodiments, a method of applying markings comprises applying a binder to a surface, wherein the binder is colorless; dropping glass elements onto the binder, wherein the glass elements are colored; and dropping retroreflective elements onto the binder, wherein the retroreflective element are colored.

In some embodiments, the glass elements and the retroreflective elements are positioned on top of the binder.

In some embodiments, the glass elements and the retroreflective elements are the same color.

In some embodiments, the step of dropping glass elements onto the binder is performed before the step of dropping retroreflective elements onto the binder.

In some embodiments, the step of dropping retroreflective elements onto the binder is performed before the step of dropping glass elements onto the binder.

In some embodiments, the step of dropping glass elements onto the binder is performed at the same time as the step of dropping retroreflective elements onto the binder.

In some embodiments, the glass elements may have an average size of 8-70 US Mesh.

In some embodiments, the average size of the glass elements is smaller than the average size of the retroreflective elements.

In some embodiments, the markings have a skid resistance of up to 75 BPN.

In some embodiments, the markings have a skid resistance of up to 82 BPN.

In some embodiments, the method further comprises heating the glass elements before the step of dropping glass elements onto the binder.

In some embodiments, the method further comprises heating the retroreflective elements before the step of dropping retroreflective elements onto the binder.

In some embodiments, the glass elements are manufactured from recycled glass.

In an exemplary embodiment, a skid-resistant marking comprises a binder applied to a surface, glass elements positioned on top of the binder, and retroreflective elements positioned on top of the binder. The binder is colorless, the glass elements are colored, and the retroreflective element are colored.

In some embodiments, the glass elements may have an average size of 8-70 US Mesh.

In some embodiments, the average size of the glass elements is smaller than the average size of the retroreflective elements.

In some embodiments, the marking has a skid resistance of up to 75 BPN.

In some embodiments, the marking has a skid resistance of up to 82 BPN.

In some embodiments, the glass elements are manufactured from recycled glass.

In some embodiments, the binder consists of resin and fillers.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, aspects, features, advantages and possible applications of the present innovation will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings. Like reference numbers used in the drawings may identify like components.

FIG. 1 is a schematic representation of an exemplary retroreflective marking system.

DETAILED DESCRIPTION OF THE INVENTION

The following description is of exemplary embodiments and methods of use that are presently contemplated for carrying out the present invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles and features of various aspects of the present invention. The scope of the present invention is not limited by this description.

The problems encountered in current roadway marking systems are resolved in many respects by the present embodiments, which utilize a binder, glass elements, and retroreflective elements to form a retroreflective marking system with adequate color, retroreflectivity, and skid resistance. While present embodiments overcome problems encountered by existing roadway marking systems, the scope of the present invention is not limited to a retroreflective roadway marking system, and it is understood that the described retroreflective marking system may be applied to any surface on which markings can be made, including but not limited to roadways, highways, bus lanes, bike lanes, crosswalks, flooring in factories or other industrial settings, and any other suitable surface.

FIG. 1 shows a schematic representation of an exemplary retroreflective marking system. In exemplary embodiments, the marker 1000 comprises a binder 100, glass elements 102, and retroreflective elements 104, wherein the glass elements 102 and the retroreflective elements 104 are positioned on top of or substantially on top of the binder 100.

In exemplary embodiments, the binder 100 may be colorless or substantially colorless (i.e., a binder with no pigments). It is contemplated that the binder 100 may comprise resin and fillers. A variety of binder materials may be used for the binder 100, including but not limited to waterborne acrylics, epoxy, polyester, polyuria, polyurethane, or any other suitable materials. It is further contemplated that the binder 100 may not contain titanium oxide.

The binder 100 may be applied to a surface (e.g., roadways, highways, bus lanes, bike lanes, crosswalks, flooring in factories or other industrial settings, and any other suitable surface). The binder 100 may have any thickness when applied to the surface. In a preferred embodiment, the binder may have a wet mil thickness between 15-45 mil, preferably between 20-40 mil.

In exemplary embodiments, the glass elements 102 may be colored (i.e., pigmented). The glass elements 102 may comprise any color, such as white, yellow, orange, blue, green, or any other suitable color. The glass elements 102 may be made from recycled clear glass. For example, recycled clear glass may be coated with an appropriate color to manufacture the glass elements 102. The glass elements 102 may have a refractive index of 1.5. It is contemplated that all of the glass elements 102 may have the same or substantially the same color. Alternatively, the glass elements 102 may be a mixture of one or more colors. In a preferred embodiment, the glass elements 102 are Color-Lane™ colored glass aggregates or elements sold by Potters Industries Inc. of Malvern, PA, U.S.A. or equivalent materials.

In exemplary embodiments, the glass elements 102 may be positioned on top of the binder 100, such that a substantial portion the glass elements 102 is exposed (i.e., not in contact with the binder 100). The exposed portion of the glass elements 102 provides color to the marker 1000 such that a motorist or pedestrian may see where surfaces are marked. It is contemplated that as the exposed portion of the glass elements 102 increases, the more color may be seen by a motorist or pedestrian.

It is further contemplated that the position of the glass elements 102 on top of the binder 100 provides improved skid resistance relative to embodiments wherein like elements are provided within a binder. Generally, for roadway markings, the skid resistance is expected to be a minimum of 35 BPN (British Pendulum Number) and preferably between 45-50 BPN. Moreover, for other lane markings (e.g., crosswalks, bike lanes, bus lanes), the skid resistance is expected to be between 40-45 BPN. The markers 1000 described herein can achieve a skid resistance up to 75 BPN, and more preferably up to 82 BPN. The skid resistance may be adjusted by adjusting the amounts of glass elements 102 dropped on the binder 100.

The glass elements 102 may be crushed glass. The glass elements 102 may have an average size of 8-70 US Mesh. A preferred size of the glass elements 102 is dependent on the thickness of the binder 100. The glass elements 102 may all have the same or substantially the same size and geometry. Alternatively, the glass elements 102 may be a mixture of different or substantially different sizes and geometries. It is contemplated that the percent roundness of the glass elements 102 may be less than or equal to 25%.

The glass elements 102 may comprise heavy metals, including but not limited to arsenic, antimony, lead, or any other heavy metal and mixtures thereof. It is contemplated that the amount of heavy metals in the glass elements 102 is less than 100 ppm.

In exemplary embodiments, the retroreflective elements 104 may comprise a retroreflective surface, wherein retroreflective is understood to mean the ability of a material to reflect light back to the light's source. For example, the retroreflective elements 104 may receive light from passing vehicles and reflect the light back to motorists, thereby alerting motorists of the location of the marker 1000. The retroreflective elements 104 are responsible for reflecting light to a motorist or pedestrian, such that a motorist or pedestrian may see where surfaces are marked. It is contemplated that the retroreflectivity of the retroreflective elements 104 may increase visibility of a marker 1000 in dark and otherwise hard-to-see conditions. The retroreflective elements 104 may have a refractive index between 1.7-2.4, preferably between 1.9-2.1.

In exemplary embodiments, the retroreflective elements 104 may be colored (i.e., pigmented). The retroreflective elements 104 may comprise any color, such as white, yellow, orange, blue, green, or any other suitable color. It is contemplated that all of the retroreflective elements 104 may have the same or substantially the same color. Alternatively, the retroreflective elements 104 may be a mixture of one or more colors. In a preferred embodiment, the retroreflective elements 104 are VisiMax® sold by Potters Industries Inc. of Malvern, PA, U.S.A. or equivalent materials.

It is contemplated that all of the glass elements 102 and all of the retroreflective elements 104 may comprise the same color, such that a consistent color is visible to a motorist or pedestrian. For example, white glass elements may be used with VisiMax® white, or yellow glass elements may be used with VisiMax® yellow. In alternative examples, blue glass elements may be used with VisiMax® blue to designate handicapped locations, or green glass elements may be used with VisiMax® green to designate bike lanes. Alternatively, the glass elements 102 and the retroreflective elements 104 may be a mixture of one or more colors.

In exemplary embodiments, the retroreflective elements 104 may be positioned on top of the binder 100, such that a substantial portion the retroreflective elements 104 is exposed (i.e., not in contact with the binder 100). The exposed portion of the retroreflective elements 104 provides reflected light back to motorists or pedestrians. It is contemplated that as the exposed portion of the retroreflective elements 104 increases, the retroreflectivity of the retroreflective elements 104 increases. The retroreflective elements 104 may have an average size of 8-20 US mesh, preferably 10-18 US Mesh.

In embodiments wherein more than one color is desired, it is contemplated that the disclosed retroreflective marking system provides for advantages over current marking systems. For example, with regard to the disclosed system, in embodiments wherein a colorless or substantially colorless binder 100 is used, the color of the marker 1000 may be changed by simply changing out glass elements 102 and/or retroreflective elements 104 of a first color with glass elements 102 and/or retroreflective elements 104 of a second color. In other words, the binder 100 remains constant, and it is not necessary to flush lines housing the binder 100. In contrast, with regard to existing marking systems, in situations wherein colored binders are used, the color of a marker can only be changed by using a binder of a first color, flushing the line free of the first binder, and then filling the line with a binder of a second color. Such a process is slow, inefficient, and wasteful.

It is contemplated that the average size of the glass elements 102 should be equal or smaller than the average size of the retroreflective elements 104. It is contemplated that the size of the glass elements 102 may interfere with the retroreflectivity of the retroreflective elements 104. As described in the Examples, the retroreflectivity of the retroreflective elements 104 increases when the size of the glass elements 102 is equal or smaller than the size of the retroreflective elements 104. The retroreflective elements 104 may all have the same or substantially the same size, geometry, and refractive index. Alternatively, the retroreflective elements 104 may be a mixture of different or substantially different sizes, geometries, and refractive indexes.

In an exemplary method for applying a pigmented retroreflective marking system, the binder 100 is first applied to a surface (e.g., roadways, highways, bus lanes, bike lanes, crosswalks, flooring in factories or other industrial settings, and any other suitable surface). It is contemplated that the binder 100 may be applied to a surface of any orientation, incline, angle, etc. As stated above, the binder 100 may have any thickness. The glass elements 102 may be dropped on the binder 100, such that the glass elements 102 may be positioned on top of the binder 100. The glass elements 102 may be dropped on the binder 100 at any coverage rate or density suitable to create a colored marker 1000. The glass elements 102 may be applied to a relatively thin layer of binder 100. A preferred coverage rate is dependent on the desired color requirement and may be adjusted accordingly. It is contemplated that the glass elements 102 may be dropped on the binder at a coverage rate of 5-30 lbs. per 100 sq. feet.

The retroreflective elements 104 may be dropped on the binder 100, such that the retroreflective elements 104 may be positioned on top of the binder 100. The retroreflective elements 104 may be dropped on the binder 100 at any coverage rate or density suitable to create a retroreflective marker 1000. The retroreflective elements 104 may be applied to a relatively thin layer of binder 100. In a preferred embodiment, the retroreflective elements 104 may have a density of 2.4-2.5 g/cc.

In an exemplary embodiment, the glass elements 102 may be dropped before the retroreflective elements 104. In an alternative embodiment, the retroreflective elements 104 may be dropped before the glass elements 102. In another alternative embodiment, the glass elements 102 and the retroreflective elements 104 may be dropped simultaneously.

In an exemplary embodiment, the glass elements 102 and the retroreflective elements 104 may be dropped simultaneously with the binder 100.

It is contemplated that the glass elements 102 and the retroreflective elements 104 may be dropped at a height (i.e., distance between binder 100 and the glass elements 102 and/or the retroreflective elements 104) so as to not splatter the binder 100.

It is contemplated that the glass elements 102 may be heated prior to being dropped on the binder 100 to assist in embedding the glass elements 102 in the binder 100. It is further contemplated that the retroreflective elements 104 may be heated prior to being dropped on the binder 100 to assist in embedding the retroreflective elements 104 in the binder 100.

It is contemplated that the combination of the binder 100, the glass elements 102, and the retroreflective elements 104 collectively contribute to a colored retroreflective marker 1000 with a surprisingly high brightness under wet, dry, clear or foggy conditions. It is contemplated that a relatively thin binder 100 may be thick enough to maintain the positions of the glass elements 102 and the retroreflective elements 104 in any condition.

EXAMPLES

The following examples serve to illustrate certain aspects of the disclosure and are not intended to limit the disclosure.

Example 1: Colored Glass Elements and VisiMax® in Clear Epoxy Binder

In a plastic beaker, 20 grams of clear epoxy and 20 grams of epoxy hardener were mixed at room temperature for 1 minute and the resulting epoxy binder was drawn down on a 6×18 inch glass panel using a 4×4″ blade with 30 mil gap. From a drop box, white colored glass elements were first dropped, followed by VisiMax® white (double drop, DD). Also, yellow colored glass elements were first dropped, followed by VisiMax® yellow (double drop, DD). Details of drop rates are shown in Table 1.

TABLE 1 Retroreflectivity in Products clear epoxy (mcd) Color-Lane ™ white, 15 lbs. 25 Color-Lane ™ white/VisiMax ® white, 5/10 727 lbs., DD Color-Lane ™ white (20/30 Mesh)/ 768 VisiMax ® white, 5/10 lbs., DD Color-Lane ™ yellow, 15 lbs. 18 Color-Lane ™ yellow/VisiMax ® yellow 523 5/10 lbs., DD Color-Lane ™ yellow 20/40 Mesh, 15 lbs. 15 Color-Lane ™ yellow 20/40 Mesh/ 751 VisiMax ® yellow, 5/10 lbs., DD Color-Lane ™ yellow 40/70 Mesh, 15 lbs 18 Color-Lane ™ yellow 40/70 Mesh/ 801 VisiMax ® yellow, 5/10 lbs., DD

Both white and yellow markings gave good retroreflectivity. As the size of colored glass aggregates decreases, the retroreflectivity increased because of less interference for incoming light.

Example 2: Colored Glass Elements and VisiMax® in Clear Dow 1K Binder

In a plastic beaker, 50 grams of clear Dow 1K waterborne acrylic binder was stirred well and drawn down on a 6×18 inch glass panel using a 4×4″ blade with 30 mil gap. From a drop box, white (or yellow) colored glass elements were first dropped, followed by VisiMax® white (or yellow) (double drop, DD). Details of drop rates are shown in Table 2.

TABLE 2 Retroreflectivity in 1K Products clear paint (mcd) Color-Lane ™ white/VisiMax ® white, 5/10 912 lbs., DD Color-Lane ™ yellow/VisiMax ® yellow, 819 5/10 lbs., DD Color-Lane ™ yellow 20/40 Mesh/ 992 VisiMax ® yellow, 5/10 lbs., DD Color-Lane ™ yellow 40/70 Mesh/ 974 VisiMax ® yellow, 5/10 lbs., DD

As in clear epoxy, both white and yellow markings gave good retroreflectivity. As the size of colored glass aggregates decreases the retroreflectivity increased because of less interference for incoming light.

Example 3: Skid Resistance

The panels described above in Example 2 were measured for skid resistance and showed the following values in Table 3.

TABLE 3 British Pendulum Products Number (BPN) Color-Lane ™ white/VisiMax ® white, 5/10 80.4 lbs., DD Color-Lane ™ yellow/VisiMax ® yellow, 79.2 5/10 lbs., DD Color-Lane ™ yellow 20/40 Mesh/ 82.8 VisiMax ® yellow, 5/10 lbs. DD Color-Lane ™ yellow 40/70 Mesh/ 80 VisiMax ® yellow, 5/10 lbs. DD

Example 4: Skid Resistance (Comparative Example)

Existing standard highway lane marking beads and optical elements were measured for skid resistance and compared with combinations of glass elements and retroreflective elements as described herein. Results are shown in Table 4.

TABLE 4 British Pendulum Products Number (BPN) Standard Highway Beads AASHTO Type I 43 AASHTO Type II 52 AASHTO Type IV 54 VisiUltra 53 Optical Elements VisiMax ® White 65 VisiMax ® Yellow 68 3M ™ Element White 62 3M ™ Element Yellow 57 Glass and Retroreflective Elements Color-Lane ™ white/VisiMax ® white, 5/10 75 lbs. Color-Lane ™ yellow/VisiMax ® yellow, 77 5/10 lbs. Color-Lane ™ white/3M ™ Element Yellow, 82 5/10 1bs. Color-Lane ™ yellow / 3M ™ Element 81 Yellow, 5/10 lbs. Color-Lane ™ white 18/30 Mesh/VisiMax ® 61 white, 25/5 lbs.

It should be understood that modifications to the embodiments disclosed herein can be made to meet a particular set of design criteria. For instance, the number of or configuration of components or parameters may be used to meet a particular objective.

It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternative embodiments may include some or all of the features of the various embodiments disclosed herein. For instance, it is contemplated that a particular feature described, either individually or as part of an embodiment, can be combined with other individually described features, or parts of other embodiments. The elements and acts of the various embodiments described herein can therefore be combined to provide further embodiments.

It is the intent to cover all such modifications and alternative embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof. Additionally, the disclosure of a range of values is a disclosure of every numerical value within that range, including the end points. Thus, while certain exemplary embodiments of the device and methods of making and using the same have been discussed and illustrated herein, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims. 

What is claimed is:
 1. A method of applying markings comprising: applying a binder to a surface, wherein the binder is colorless, dropping glass elements onto the binder, wherein the glass elements are colored, and dropping retroreflective elements onto the binder, wherein the retroreflective element are colored.
 2. The method of claim 1, wherein the glass elements and the retroreflective elements are positioned on top of the binder.
 3. The method of claim 1, wherein the glass elements and the retroreflective elements are the same color.
 4. The method of claim 1, wherein the step of dropping glass elements onto the binder is performed before the step of dropping retroreflective elements onto the binder.
 5. The method of claim 1, wherein the step of dropping retroreflective elements onto the binder is performed before the step of dropping glass elements onto the binder.
 6. The method of claim 1, wherein the step of dropping glass elements onto the binder is performed at the same time as the step of dropping retroreflective elements onto the binder.
 7. The method of claim 1, wherein the glass elements may have an average size of 8-70 US Mesh.
 8. The method of claim 1, wherein the average size of the glass elements is smaller than the average size of the retroreflective elements.
 9. The method of claim 1, wherein the markings have a skid resistance of up to 75 BPN.
 10. The method of claim 1, wherein the markings have a skid resistance of up to 82 BPN.
 11. The method of claim 1, further comprising heating the glass elements before the step of dropping glass elements onto the binder.
 12. The method of claim 1, further comprising heating the retroreflective elements before the step of dropping retroreflective elements onto the binder.
 13. The method of claim 1, wherein the glass elements are manufactured from recycled glass.
 14. A skid-resistant roadway marking comprising: a binder applied to a surface, wherein the binder is colorless, glass elements positioned on top of the binder, wherein the glass elements are colored, and retroreflective elements positioned on top of the binder, wherein the retroreflective element are colored.
 15. The roadway marking of claim 14, wherein the glass elements may have an average size of 8-70 US Mesh.
 16. The roadway marking of claim 14, wherein the average size of the glass elements is smaller than the average size of the retroreflective elements.
 17. The roadway marking of claim 14, wherein the marking has a skid resistance of up to 75 BPN.
 18. The roadway marking of claim 14, wherein the marking has a skid resistance of up to 82 BPN.
 19. The roadway marking of claim 14, wherein the glass elements are manufactured from recycled glass.
 20. The roadway marking of claim 14, wherein the binder consists of resin and fillers. 